This winter in the Midwest has been very mild, so for President’s Day weekend we were looking for a fun, new day trip to take with the family. I put my husband in charge and he planned a trip to Cave of the Mounds, in southwest Wisconsin. Cave of the Mounds is a National Natural Landmark, and is called the jewel box of American caves. We couldn’t believe we had never heard of this place! Located 25 miles west of Wisconsin, it was about a 2.5 hour drive from our home base of Schaumburg. There is plenty of parking above the cave site, and then we walked down to the visitor’s center and gift shop.
Tours of the caves leave on the hour on weekends, and a few times a day during the week. We bought tickets for our cave tour, and then had a few minutes to browse the gift shop and visitors center. We found a coupon for a free small bag of sluicing material, so we headed over to the visitor’s center so Landon could try his luck at finding treasure! From the looks of it, there is a really cool outdoor sluice that operates in the summer. For winter, there is a small trough inside the visitor’s center. The sluicing material had gems and fossils, and Landon was thrilled with what he found! The “goodies” are in the bag with a bunch of sand, so we almost didn’t need the water to separate the sand from the fossils. Most of the fossils were little aquatic animals, but there were a few shark teeth and dinosaur bone pieces mixed in. A convenient chart detailing the different types of fossils available was posted several places around the room so we could identify our treasures.
Throughout the visitor’s center, several stations were laid out for discovery by the kiddos. There were things to touch, tons of bones to look at in cases, and a neat poster with the different dinosaur time periods. There was also a coloring station with various coloring pages and animal tracks stamps. Cave of the Mounds did a great job having some engaging activities for the kiddos while we waited for our tour to start!
When it was almost time for our tour, we made our way over to the gift shop, which also serves as the cave entrance. In this aspect, this cave was unique-the cave entrance was indoors! The gift shop was filled with a variety of fossils, tons of kid’s toys and souvenirs, and gems. There was a geode cracking station that Landon really wanted to try, but it was time for our tour!
The cave tour was (understandably) not stroller accessible. Because the cave features are so fragile, we opted to put Owen in our carrier in the more comfortable back carry so that he could enjoy the tour without touching the fragile formations. Landon did great following the rules and being careful in the cave. At one point during the tour, the path gets pretty tight and the tour guide told me to switch Owen to front carry, so we carried him in front for the remainder of the hour-long tour. We were glad that I carried Owen, because I think in some spots he would have hit his head had Austin carried him.
For the first few minutes of the tour, we watched a movie about the formation and discovery of Cave of the Mounds. This cave was formed 1-2 million years ago when the limestone of one of the Blue Mounds of Wisconsin was underneath the water table. Acidic water from the surface began to eat away at the limestone and form a crack, which then dripped down and eroded the stone, forming the cave. Calcite then dripped into the cave, forming the stalactites, stalagmites, and flowstones. It can take up to 150 years to form 1 cubic inch of calcite, so the beauty of this cave has really been a million years in the making! Some of the stalagmites were almost reaching the ceiling!
This cave was discovered in an unusual way. A family settled the area in the 1800s during the lead rush. In 1939, the area was a limestone quarry and a routine blast at the quarry tore the face off of the quarry and exposed a portion of the cave system. There was no natural entrance to the cave before then, so there are no surface life forms in the cave. What a discovery! Soon, they installed lights and walkways and opened the cave up for people to enjoy. Now, it is a national natural landmark and is preserved by the government for our enjoyment.
After the film, our guide took us down into the cave. It stays around 50 degrees in the cave year round, so light jackets made it more comfortable for us! Our guide pointed out the crack in the ceiling that produced the stalagmites and stalactites that were admired along the sides of the walkway. It was unbelievable how tall some of the formations were! He also pointed out the 6-foot cephalopod shell fossil in the ceiling. I couldn’t believe we were looking at natural structures that were older than a 6-foot cephalopod (long, skinny, squid-like thing). Wisconsin was once underwater as part of a shallow, inland sea and this creature lived in that sea.
Normal calcite is typically white or yellow, and so our guide explained how other colors are introduced to the cave. The grays and blues are introduced by dissolved manganese, and browns and reds from iron. What makes this cave so awesome is the size, quantity and variety of formations. On our hour-long tour, we explored several caverns of this cave system and discussed a different formation or aspect of the cave at each stop. The cave was well-lit in our immediate area- they try to conserve the cave by switching off the lights after we pass through an area. Most of the tour took place in big, open caverns, with one slightly claustrophobic/tight squeeze between two walls to get to another area of the cave system.
Our guide showed us how there are tiny creatures that live in the pools of water in caves. There was also a place in the cave where a chunk of stalactites had fallen off of the ceiling and landed upright on the ground, so that they looked like stalagmites. The guide explained that perhaps a river of water knocked the stalactites off and gently placed them on the ground, relatively intact! So cool! Because of this feature, we were able to see that stalactites are actually hollow inside! The water droplets drip down the middle and calcite forms around the sides. The cute, little hollow stalactites are called soda straws!
When water trickles along the roof of a cave, ribbon stalactites, or cave bacon form. There were many examples of ribbon stalactites in the cave, including blue and gray ones with manganese in them. Our guide did a wonderful job explaining everything in an engaging, but easy to understand way that was interesting for adults and for our 4-year-old as well! We ended our tour with an impressive demonstration of phosphorescence. After having the lights on in one area of the cave for a few minutes, our guide turned the lights off and in the blurry photo above, you can see the glow of the rocks from the absorbed light. There were two demonstrations of the phosphorescent ability of rocks, where they turned out all of the lights in our part of the cave, so it was completely black. The kids in our group did amazingly well with this, I can imagine if a kid is afraid of the dark, this would be kinda freaky. Just make sure your kids are close during this time, so they know they are safe!
I came away from our tour in awe of the beauty of the natural world! What other amazing caves could be beneath our feet and we never even know it? We wrapped up our time at the Cave of the Mounds with a fossil dig and nature walk. The fossil digging in a covered, but open-air area off of the gift shop is free, but you pay for what you keep. There were boards with size guides, and if you filled your board, you got a slight discount. I think we got 8 fossils for $6, but I’m not exactly sure. Landon was in heaven digging in the dirt and finding actual fossils! We discovered several shark teeth, a piece of dinosaur bone, and some pretty rocks. Our only sticking point was that Landon wanted to identify what kind of dinosaur the bone was from, but with just a 1-inch square chunk, this proved to be impossible. Owen enjoyed scooping up sand, and trying to eat anything that he found!
Our nature walk led us to this historic red barn, which is part of the Cave of the Mounds campus, but was closed for the winter season. Cave of the Mounds was a great family-friendly activity for our mini-road trip. Landon loved the sluicing and digging for fossils! The cave system was an amazing natural wonder! Our kids are pretty fearless and interested in geology/caves/paleontology, so this was a great activity for our four-year-old. I would recommend this activity for elementary school students and above, and maybe not for kids that are really afraid of the dark. There seemed to be a small snack in the visitor’s center, but otherwise, I would recommend eating beforehand and bringing snacks for the kiddos. If you’re ever near Madison, WI, check out Cave of the Mounds!